HODGKIN'S DISEASE may involve any of the structures of the body. Of special interest is its presence in the spinal canal, even though this is an infrequent complication. When such involvement is suspected, an immediate decision must be made as to the nature of treatment. Four alternatives present themselves: radiation therapy, neurosurgical intervention, a combination of these two, and neglect. At the University of Minnesota Hospitals 11 cases of spinal cord compression caused by Hodgkin's disease (8 proved, 3 clinical) were observed during the period 1926-47. Experiences with the treatment of these cases will be detailed. Weil (18), in 1931, reviewed the world's literature and recorded 43 cases of central nervous system involvement secondary to Hodgkin's disease; he added 3 cases observed personally. Of the 46 patients, 40 had epidural masses, with or without involvement of the vertebrae; 2 had infectious myelitis, 2 had syringomyelia, and 2 had cerebral lesions. All of these cases were confirmed by autopsy or operation. Only 3 patients received x-ray therapy for the spinal involvement, and all 46 died within six to twelve months after onset of symptoms. Since Weil's review, isolated case reports have appeared. Cooper (2), Keschner (10), and others (9, 11, 16, 19, 20) have each added one proved case of Hodgkin's disease in the epidural space, and Rosh (14) has added two instances of compression of the spine with vertebral collapse. In 1941, Gray et al. (8) described 3 cases of proved involvement. These were observed at the University of Minnesota Hospitals and are brought up to date in the present study (Cases 2, 3, and 4 in our series). Four mechanisms have been invoked to explain the presence of spinal cord symptoms, by Weil (18), Allen and Mercer (1), Weber (17) and others (2, 8). These are as follows: a. Epidural deposits of Hodgkin's tissue extending from involved cervical, mediastino- bronchial, or retroperitoneal lymph nodes, by way of the lymph channels of the nerve roots, into the epidural space. The dura is supposedly effective in blocking further invasion. b. Destruction of the bodies of vertebrae with collapse and direct mechanical compression of the spinal cord, or spread from the diseased spine epidurally. c. Mechanical compression of the blood vessels within the intervertebral foramina or just outside of the spinal cord, causing impaired circulation to the cord-myelomalacia. d. Rarely, degenerative or inflammatory changes within the cord, such as syringomyelia or myelitis, with or without epidural masses. Winkelman (20) attributed the presence of epidural masses in some cases to vascular metastases.